1 files changed, 104 insertions, 0 deletions
diff --git a/libcxx/test/std/utilities/expected/expected.void/monadic/or_else.pass.cpp b/libcxx/test/std/utilities/expected/expected.void/monadic/or_else.pass.cpp
new file mode 100644
index 000000000000..13e341c6d20c
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+++ b/libcxx/test/std/utilities/expected/expected.void/monadic/or_else.pass.cpp
@@ -0,0 +1,104 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17, c++20
+
+// <expected>
+
+// template<class F> constexpr auto or_else(F&& f) &;
+// template<class F> constexpr auto or_else(F&& f) const &;
+// template<class F> constexpr auto or_else(F&& f) &&;
+// template<class F> constexpr auto or_else(F&& f) const &&;
+
+#include <expected>
+#include <concepts>
+#include <cassert>
+#include <type_traits>
+#include <utility>
+
+constexpr void test_val_types() {
+  // Test & overload
+  {
+    auto l = [](auto) -> std::expected<void, long> { return {}; };
+    std::expected<void, int> v(std::unexpected<int>(1));
+    std::same_as<std::expected<void, long>> decltype(auto) val = v.or_else(l);
+    assert(val.has_value());
+  }
+
+  // Test const& overload
+  {
+    auto l = [](auto) -> std::expected<void, long> { return {}; };
+    const std::expected<void, int> v(std::unexpected<int>(1));
+    std::same_as<std::expected<void, long>> decltype(auto) val = v.or_else(l);
+    assert(val.has_value());
+  }
+
+  // Test && overload
+  {
+    auto l = [](auto) -> std::expected<void, long> { return {}; };
+    std::expected<void, int> v(std::unexpected<int>(1));
+    std::same_as<std::expected<void, long>> decltype(auto) val = std::move(v).or_else(l);
+    assert(val.has_value());
+  }
+
+  // Test const&& overload
+  {
+    auto l = [](auto) -> std::expected<void, long> { return {}; };
+    const std::expected<void, int> v(std::unexpected<int>(1));
+    std::same_as<std::expected<void, long>> decltype(auto) val = std::move(v).or_else(l);
+    assert(val.has_value());
+  }
+}
+
+constexpr void test_fail() {
+  auto never_called = [](auto) -> std::expected<void, long> {
+    assert(false);
+    return std::expected<void, long>(std::unexpected<long>(5));
+  };
+
+  // Test & overload
+  {
+    std::expected<void, int> v;
+    std::same_as<std::expected<void, long>> decltype(auto) val = v.or_else(never_called);
+    assert(val.has_value());
+  }
+
+  // Test const& overload
+  {
+    const std::expected<void, int> v;
+    std::same_as<std::expected<void, long>> decltype(auto) val = v.or_else(never_called);
+    assert(val.has_value());
+  }
+
+  // Test && overload
+  {
+    std::expected<void, int> v;
+    std::same_as<std::expected<void, long>> decltype(auto) val = std::move(v).or_else(never_called);
+    assert(val.has_value());
+  }
+
+  // Test const&& overload
+  {
+    const std::expected<void, int> v;
+    std::same_as<std::expected<void, long>> decltype(auto) val = std::move(v).or_else(never_called);
+    assert(val.has_value());
+  }
+}
+
+constexpr bool test() {
+  test_fail();
+  test_val_types();
+  return true;
+}
+
+int main(int, char**) {
+  test();
+  static_assert(test());
+
+  return 0;
+}